Thermal insulation paper capable of resisting 1600 DEG C and preparation method of thermal insulation paper
By using alumina microfiber, magnesium silicate fiber and nanoalumina powder in temperature-resistant heat-resistant insulation paper and chemical bonding, the problem of poor thermal insulation performance in high-temperature environments is solved, and high-efficiency thermal insulation, high-temperature and high-strength thermal insulation paper is achieved.
Patent Information
- Application Number
- CN202510002177.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-02
- Publication Date
- 2025-02-28
AI Technical Summary
The existing temperature-resistant heat-insulating paper has poor thermal insulation performance in high temperature environments, especially in extreme environments above 1600℃, which is difficult to meet the needs of efficient thermal insulation.
Alumina microfiber, magnesium silicate fiber and nanoalumina powder are used as the main components, and high-strength, flame-retardant, high-temperature insulation paper is formed by chemical bonding of amino-containing silane coupling agent, aluminum sol and silicone.
It achieves efficient thermal insulation performance in an environment above 1600℃, improves the temperature and tensile strength of thermal insulation paper, and reduces the thermal conductivity, making it suitable for applications in high-temperature and high-pressure environments.
Smart Images
Figure BDA0005225648840000051 
Figure BDA0005225648840000061
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of special paper, and in particular to a 1600°C resistant heat-insulating paper and a preparation method thereof. Background Art
[0002] The application of thermal insulation materials in the field of energy conservation and emission reduction is a relatively effective measure. Thermal insulation materials are being used more and more widely in many fields due to their excellent thermal insulation performance. Among them, fibrous thermal insulation materials are more commonly used. Their excellent thermal stability, corrosion resistance, high temperature resistance, thermal insulation and thermal shock resistance have been widely used in the fields of thermal insulation of thermal pipes, thermal insulation of high-temperature industrial kiln walls, aerospace and military fields.
[0003] Heat-resistant insulation paper is mainly composed of heat-resistant fiber, binder and additives. Heat-resistant fiber includes organic fiber, inorganic fiber and metal fiber. Among them, inorganic fiber is widely used, such as aluminum silicate fiber, diatomaceous earth fiber, etc. Its production process mainly includes wet method and dry method. The wet process is to mix the heat-resistant fiber with the binder and then form it through a papermaking machine; the dry process is to mix the heat-resistant fiber with the binder and then make it through drying, pressing and other processes. Heat-resistant insulation paper has the following advantages: excellent thermal stability, can be used for a long time in high temperature environment; good corrosion resistance, suitable for a variety of corrosive environments; high temperature resistance, the maximum use temperature can reach more than 1000℃; good thermal insulation performance, reduce heat loss; thermal shock resistance, adapt to temperature changes.
[0004] Although the thermal insulation performance of heat-resistant insulation paper is relatively good, its thermal insulation performance still needs to be further improved in some extreme environments such as high temperature and high pressure. Especially in high temperature environment, the thermal insulation performance is still poor. Summary of the invention
[0005] In order to solve the technical problem that the thermal insulation effect of thermal insulation paper is poor in a high temperature environment, a 1600°C resistant thermal insulation paper and a preparation method thereof are provided. The thermal insulation paper of the present invention has good temperature resistance and heat insulation performance, solves the problem of low temperature resistance of thermal insulation paper, has low production cost, and is high-quality thermal insulation paper.
[0006] To solve the above problems, the present invention is implemented through the following technical solutions:
[0007] A method for preparing 1600°C resistant thermal insulation paper comprises the following steps:
[0008] S1. Dissolve alumina ultrafine fibers and magnesium silicate fibers in water, add an amino-containing silane coupling agent and mix, then add aluminum sol and mix; then add gas phase nano alumina powder and silicone emulsion to prepare the slurry;
[0009] S2, subsequently carrying out wet paper sheet making, suction dehydration, drying, and slitting in sequence to obtain 1600°C resistant heat insulation paper;
[0010] The length of the alumina ultrafine fiber is 1-5 mm and the diameter is less than 10 μm; the length of the magnesium silicate fiber is 2-4 mm and the diameter is in the range of 50-150 μm, wherein the magnesium oxide content is in the range of 20%-25%; the particle size of the gas phase nano alumina powder is less than 30 nm;
[0011] The mass ratio of the ultrafine alumina fibers to the magnesium silicate fibers is 2-3:1, and the gas phase nano alumina powder accounts for 5%-10% of the total weight of the fibers.
[0012] Furthermore, the total addition amount of the aluminum sol, the amino-containing silane coupling agent, and the organic silicon emulsion is 1%-10% of the total weight of the fiber.
[0013] Furthermore, the mass ratio of the aluminum sol, the amino-containing silane coupling agent, and the silicone emulsion is 1-3:0.1:1.
[0014] Preferably, the mass percentage of the aluminum sol is 5-50% and the colloidal particle size is 5-30nm; the amino-containing silane coupling agent is selected from one or more of γ-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, N-aminoethyl-3-aminopropyltriethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, ureapropyltriethoxysilane, γ-ureapropyltriethoxysilane, and 3-(4-ureaamino)propyltriethoxysilane. By first adding an amino-containing silane coupling agent to pre-bond with functional groups such as hydroxyl and carboxyl groups on the fiber surface, and then adding acidic and positively charged aluminum sol, on the one hand, the terminal amino group destroys the colloid stability of the aluminum sol, causing the positively charged colloidal particles to precipitate and anchor on the fiber surface containing functional groups such as hydroxyl and carboxyl groups, making the fibers firmly bonded, and on the other hand, the acidic condition of the aluminum sol accelerates the hydrolysis of the silane coupling agent, forming hydrogen bonds on the fiber surface, and subsequently adding nano-alumina particles to disperse them evenly in the system. With the addition of silicone, the silicone bonds to the nano-alumina particles and combines with the silane coupling agent on the fiber, and is dried and dehydrated under subsequent heating conditions. These are connected by covalent bonds, so that the thermal insulation paper has better strength.
[0015] Furthermore, the decomposition in S1 is carried out by stirring at a low speed range of 100-400 r / min until there are no flocs; the mixing in S1 is carried out by stirring and mixing at 400-600 r / min for at least 15 minutes; and the slurry preparation in S2 is carried out at a high speed range of 800-1200 r / min for at least 15 minutes.
[0016] Furthermore, the wet paper sheet has a web concentration of 0.1wt%-0.25wt% and a paper basis weight of 100-500g / m 2 .
[0017] Furthermore, the suction dehydration is to make the dryness of the formed wet paper sheet 25%-35%.
[0018] Furthermore, the drying is carried out simultaneously with infrared heating drying under microwave conditions, the infrared heating temperature is 120-180° C., the microwave frequency is in the range of 2000-2500 MHz, the power is in the range of 2000-4000 W, and the product is dried to a dryness of more than 95%.
[0019] Another aspect of the present invention provides 1600° C. resistant thermal insulation paper prepared by the above method.
[0020] Beneficial technical effects:
[0021] The present invention uses slender alumina ultrafine fibers as main fibers to support the skeleton and ensure the temperature resistance of 1600°C; uses magnesium silicate fibers with a relatively large diameter as auxiliary filling functional fibers to play a reinforcing role, and at the same time forms a denser ceramic layer at high temperature to achieve efficient flame retardancy; uses nano-scale gas-phase alumina powder as a filler to fill the gaps between fibers, and enhances the heat insulation effect through optical reflection; the fine fibers and the coarse fibers are first bonded by an amino-containing silane coupling agent, and then effectively chemically bonded by aluminum sol and organic silicon, so that the obtained special paper has high strength, flame retardancy, temperature resistance of 1600°C, and low thermal conductivity at high temperatures; the preparation process of the present invention is simple and suitable for large-scale production. DETAILED DESCRIPTION
[0022] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0023] Unless otherwise specifically stated, the numerical value set forth in these embodiments does not limit the scope of the present invention. The technology and method known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology and method should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values.
[0024] The experimental methods in the following examples without specifying specific conditions are usually measured in accordance with national standards; if there is no corresponding national standard, the method is carried out in accordance with the general standard requirements or general methods.
[0025] Example 1
[0026] A method for preparing 1600°C resistant thermal insulation paper comprises the following steps:
[0027] S1. Disintegration of alumina ultrafine fibers and magnesium silicate fibers: 3 kg of alumina ultrafine fibers (chopped fibers, with an average length of 3-5 mm and an average diameter of less than 10 μm) and magnesium silicate fibers (chopped fibers, with an average length of 2-3 mm and an average diameter of 200 mesh) are prepared at a mass ratio of 2:1, mixed and added into a low-speed disperser, and stirred with water at a speed of 200 r / min until the two fibers are fully mixed without flocs;
[0028] 4.5 g of γ-aminopropyltriethoxysilane was added and stirred at 400 r / min for 20 min, and then 45 g of high-purity aluminum sol (model BRD-300B inorganic acid type, translucent to transparent liquid, solid content 50 wt%, pH value 2-3, colloidal particle size 5-10 nm) was added and mixed at 800 r / min for 60 min;
[0029] Then, 150 g of gas phase nano-alumina powder (15-30 nm) and 45 g of organosilicon emulsion were added and mixed at a speed of 800 r / min for 20 min to obtain a slurry;
[0030] S2, then enter the wet paper sheet making system, so that the pulp is made into paper with a concentration of 0.2wt% and a paper sheet basis weight of 100g / m 2 After the papermaking is completed, a formed wet paper sheet is obtained, and then it is dehydrated by suction under negative pressure until the wet paper sheet has a dryness of 35%. Then, it is simultaneously dried by infrared heating under microwave conditions. The infrared heating temperature is 130°C, the microwave frequency is 2450MHz, and the power is 2000W, and the product is dried to a dryness of more than 98%.
[0031] Example 2
[0032] A method for preparing 1600°C resistant thermal insulation paper comprises the following steps:
[0033] S1. Disintegration of alumina ultrafine fibers and magnesium silicate fibers: 4 kg of alumina ultrafine fibers (chopped fibers, with an average length of 3-5 mm and an average diameter of less than 10 μm) and magnesium silicate fibers (chopped fibers, with an average length of 2-3 mm and an average diameter of 200 mesh) are prepared at a mass ratio of 3:1, mixed and added into a low-speed disperser, and stirred with water at a speed of 200 r / min until the two fibers are fully mixed without flocs;
[0034] 6.5 g of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane was added and stirred at 400 r / min for 20 min, and then 130 g of high-purity aluminum sol (model BRD-300B inorganic acid type, translucent to transparent liquid, solid content 50 wt%, pH value 2-3, colloidal particle size 5-10 nm) was added and mixed at 800 r / min for 60 min;
[0035] Then, 320 g of gas phase nano-alumina powder (15-30 nm) and 65 g of silicone emulsion were added and mixed at a speed of 800 r / min for 20 min to obtain a slurry;
[0036] S2, then enter the wet paper sheet making system, so that the pulp is made into paper with a concentration of 0.25wt% and a paper sheet basis weight of 300g / m 2 After the papermaking is completed, a formed wet paper sheet is obtained, and then it is dehydrated by suction under negative pressure until the wet paper sheet has a dryness of 35%. Then, it is simultaneously dried by infrared heating under microwave conditions. The infrared heating temperature is 150°C, the microwave frequency is 2450MHz, and the power is 3000W, and the product is dried to a dryness of more than 98%.
[0037] Example 3
[0038] A method for preparing 1600°C resistant thermal insulation paper comprises the following steps:
[0039] S1. Disintegration of alumina ultrafine fibers and magnesium silicate fibers: 4 kg of alumina ultrafine fibers (chopped fibers, with an average length of 3-5 mm and an average diameter of less than 10 μm) and magnesium silicate fibers (chopped fibers, with an average length of 2-3 mm and an average diameter of 200 mesh) are prepared at a mass ratio of 3:1, mixed and added into a low-speed disperser, and stirred with water at a speed of 200 r / min until the two fibers are fully mixed without flocs;
[0040] 13 g of N-aminoethyl-3-aminopropyltriethoxysilane was added and stirred at 400 r / min for 20 min, and then 260 g of high-purity aluminum sol (model BRD-300B inorganic acid type, translucent to transparent liquid, solid content 50 wt%, pH value 2-3, colloidal particle size 5-10 nm) was added and mixed at 1000 r / min for 40 min;
[0041] Then, 400 g of gas phase nano-alumina powder (15-30 nm) and 130 g of silicone emulsion were added and mixed at a speed of 1000 r / min for 15 min to obtain a slurry;
[0042] S2, then enter the wet paper sheet making system, so that the pulp is made into paper with a concentration of 0.2wt% and a paper sheet basis weight of 500g / m 2 After the papermaking is completed, a formed wet paper sheet is obtained, and then it is dehydrated by suction under negative pressure until the wet paper sheet has a dryness of 30%. Then, infrared heating drying is carried out simultaneously under microwave conditions. The infrared heating temperature is 170°C, the microwave frequency is 2450MHz, and the power is 4000W, and the product is dried to a dryness of more than 98%.
[0043] Comparative Example 1
[0044] The preparation of the thermal insulation paper in this case is the same as that in Example 1, except that the fibers are only ultrafine aluminum oxide fibers.
[0045] Comparative Example 2
[0046] The preparation of the thermal insulation paper in this case is the same as that in Example 1, except that the fibers are only magnesium silicate fibers.
[0047] Comparative Example 3
[0048] The preparation of the thermal insulation paper in this case is the same as that in Example 1, except that no gas phase nano-alumina powder is added.
[0049] Comparative Example 4
[0050] The preparation of the thermal insulation paper in this case is the same as that in Example 1, except that the silane coupling agent is KH560.
[0051] Comparative Example 5
[0052] The preparation of the thermal insulation paper in this case is the same as that in Example 1, except that γ-aminopropyltriethoxysilane and aluminum sol are not added, and only silicone emulsion is used.
[0053] Comparative Example 6
[0054] The preparation of the thermal insulation paper in this case is the same as that in Example 1, except that no aluminum sol is added.
[0055] Comparative Example 7
[0056] The preparation of the thermal insulation paper in this case is the same as that in Example 1, the difference is that in S1, γ-aminopropyltriethoxysilane, high-purity aluminum sol and silicone emulsion are not added in order, but high-purity aluminum sol, γ-aminopropyltriethoxysilane and silicone emulsion are directly added to the fiber dispersion after decomposition at the same time, mixed at a speed of 800 r / min for 60 minutes, and then the gas-phase nano-alumina powder is added and slurry is prepared at a speed of 800 r / min for 20 minutes to obtain a slurry.
[0057] The thermal insulation paper of the above cases was tested for performance, and the results are shown in Table 1.
[0058] Table 1 Thermal insulation paper performance of each case
[0059]
[0060]
[0061] As can be seen from Table 1, the present invention uses slender alumina ultrafine fibers as main fibers, magnesium silicate fibers with a relatively large diameter as auxiliary filling functional fibers, and combines nano-scale vapor-phase alumina powder as a filler to fill the gaps between fibers. An amino-containing silane coupling agent, aluminum sol and silicone are added in sequence for effective chemical bonding, so that the special paper has higher strength, flame retardancy, temperature resistance of 1600°C, and lower thermal conductivity at high temperatures.
[0062] In Comparative Example 1, the fibers are only ultrafine alumina fibers, and the thermal conductivity at room temperature and the thermal conductivity at high temperature are slightly better than those in Example 1, but the maximum operating temperature and the tensile strength are lower.
[0063] In Comparative Example 2, the fibers are only magnesium silicate fibers, and the maximum operating temperature and tensile strength are higher than those in Example 1, but the thermal conductivity is also higher.
[0064] In Comparative Example 3, no gas phase nano-alumina powder is added. Since the gaps between the fibers are not filled with particles, the thermal conductivity is lower than that of Example 1, and the strength is lower than that of Example 1.
[0065] In Comparative Example 4, no amino-containing silane coupling agent is used, so that the bonding strength between the materials is lower than that in Example 1.
[0066] In Comparative Example 5, only the silicone emulsion was used, which could not effectively combine the various materials and had a very low tensile strength.
[0067] Comparative Example 6 does not contain aluminum sol, which reduces the tensile strength.
[0068] In Comparative Example 7, γ-aminopropyltriethoxysilane, high-purity aluminum sol and silicone emulsion were added in no particular order, resulting in a slightly lower tensile strength.
[0069] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.
Claims
1. A method for preparing 1600°C resistant thermal insulation paper, characterized in that: The steps include: S1. Dissolve alumina ultrafine fibers and magnesium silicate fibers in water, add an amino-containing silane coupling agent and mix, then add aluminum sol and mix; then add gas phase nano alumina powder and silicone emulsion to prepare the slurry; S2, subsequently carrying out wet paper sheet making, suction dehydration, drying, and slitting in sequence to obtain 1600°C resistant heat insulation paper; The length of the alumina ultrafine fiber is 1-5 mm and the diameter is less than 10 μm; the length of the magnesium silicate fiber is 2-4 mm and the diameter is in the range of 50-150 μm, wherein the magnesium oxide content is in the range of 20%-25%; the particle size of the gas phase nano alumina powder is less than 30 nm; The mass ratio of the ultrafine alumina fibers to the magnesium silicate fibers is 2-3:1, and the gas phase nano alumina powder accounts for 5%-10% of the total weight of the fibers.
2. The method for preparing a 1600°C resistant thermal insulation paper according to claim 1, characterized in that: The total added amount of the aluminum sol, the amino-containing silane coupling agent and the organic silicon emulsion is 1%-10% of the total weight of the fiber.
3. The method for preparing a 1600°C resistant thermal insulation paper according to claim 2, characterized in that: The mass ratio of the aluminum sol, the amino-containing silane coupling agent, and the organic silicon emulsion is 1-3:0.1:
1.
4. The method for preparing a 1600°C resistant thermal insulation paper according to claim 3, characterized in that: The mass percentage of the aluminum sol is 5-50%, and the colloidal particle size is 5-30nm; The amino-containing silane coupling agent is selected from one or more of γ-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, N-aminoethyl-3-aminopropyltriethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, ureapropyltriethoxysilane, γ-ureapropyltriethoxysilane, and 3-(4-ureaamino)propyltriethoxysilane.
5. The method for preparing a 1600°C resistant thermal insulation paper according to any one of claims 1 to 4, characterized in that: The decomposition in S1 is carried out by stirring at a low speed range of 100-400 r / min until there are no flocs; the mixing in S1 is carried out by stirring and mixing at 400-600 r / min for at least 15 minutes; the slurry preparation in S2 is carried out at a high speed range of 800-1200 r / min for at least 15 minutes.
6. The method for preparing 1600°C resistant thermal insulation paper according to any one of claims 1 to 4, characterized in that: The wet paper sheet has a concentration of 0.1wt%-0.25wt% and a basis weight of 100-500g / m 2 .
7. The method for preparing a 1600°C resistant thermal insulation paper according to any one of claims 1 to 4, characterized in that: The suction dehydration is to make the dryness of the formed wet paper sheet 25%-35%.
8. The method for preparing 1600°C resistant thermal insulation paper according to any one of claims 1 to 4, characterized in that: The drying is carried out by infrared heating under microwave conditions, the infrared heating temperature is 120-180°C, the microwave frequency is within the range of 2000-2500MHz, the power is within the range of 2000-4000W, and the product is dried to a dryness of more than 95%.
9. The 1600°C resistant thermal insulation paper obtained according to the preparation method according to any one of claims 1 to 8.